#include "env.h"
#include "env-inl.h"
#include "handle_wrap.h"
#include "node_wrap.h"
#include "util.h"
#include "util-inl.h"

#include <string.h>
#include <stdlib.h>

namespace node {

using v8::Array;
using v8::Context;
using v8::FunctionCallbackInfo;
using v8::FunctionTemplate;
using v8::HandleScope;
using v8::Integer;
using v8::Local;
using v8::Number;
using v8::Object;
using v8::String;
using v8::Value;

class ProcessWrap : public HandleWrap {
public:
    static void Initialize(Local<Object> target,
        Local<Value> unused,
        Local<Context> context)
    {
        Environment* env = Environment::GetCurrent(context);
        Local<FunctionTemplate> constructor = env->NewFunctionTemplate(New);
        constructor->InstanceTemplate()->SetInternalFieldCount(1);
        constructor->SetClassName(FIXED_ONE_BYTE_STRING(env->isolate(), "Process"));

        env->SetProtoMethod(constructor, "close", HandleWrap::Close);

        env->SetProtoMethod(constructor, "spawn", Spawn);
        env->SetProtoMethod(constructor, "kill", Kill);

        env->SetProtoMethod(constructor, "ref", HandleWrap::Ref);
        env->SetProtoMethod(constructor, "unref", HandleWrap::Unref);
        env->SetProtoMethod(constructor, "hasRef", HandleWrap::HasRef);

        target->Set(FIXED_ONE_BYTE_STRING(env->isolate(), "Process"),
            constructor->GetFunction());
    }

    size_t self_size() const override { return sizeof(*this); }

private:
    static void New(const FunctionCallbackInfo<Value>& args)
    {
        // This constructor should not be exposed to public javascript.
        // Therefore we NODE_ASSERT that we are not trying to call this as a
        // normal function.
        NODE_CHECK(args.IsConstructCall());
        Environment* env = Environment::GetCurrent(args);
        new ProcessWrap(env, args.This());
    }

    ProcessWrap(Environment* env, Local<Object> object)
        : HandleWrap(env,
            object,
            reinterpret_cast<uv_handle_t*>(&process_),
            AsyncWrap::PROVIDER_PROCESSWRAP)
    {
    }

    static void ParseStdioOptions(Environment* env,
        Local<Object> js_options,
        uv_process_options_t* options)
    {
        Local<String> stdio_key = env->stdio_string();
        Local<Array> stdios = js_options->Get(stdio_key).As<Array>();

        uint32_t len = stdios->Length();
        options->stdio = new uv_stdio_container_t[len];
        options->stdio_count = len;

        for (uint32_t i = 0; i < len; i++) {
            Local<Object> stdio = stdios->Get(i).As<Object>();
            Local<Value> type = stdio->Get(env->type_string());

            if (type->StrictEquals(env->ignore_string())) {
                options->stdio[i].flags = UV_IGNORE;
            } else if (type->StrictEquals(env->pipe_string())) {
                options->stdio[i].flags = static_cast<uv_stdio_flags>(
                    UV_CREATE_PIPE | UV_READABLE_PIPE | UV_WRITABLE_PIPE);
                Local<String> handle_key = env->handle_string();
                Local<Object> handle = stdio->Get(handle_key).As<Object>();
                NODE_CHECK(!handle.IsEmpty());
                options->stdio[i].data.stream = reinterpret_cast<uv_stream_t*>(
                    Unwrap<PipeWrap>(handle)->UVHandle());
            } else if (type->StrictEquals(env->wrap_string())) {
                Local<String> handle_key = env->handle_string();
                Local<Object> handle = stdio->Get(handle_key).As<Object>();
                uv_stream_t* stream = HandleToStream(env, handle);
                NODE_CHECK_NE(stream, nullptr);

                options->stdio[i].flags = UV_INHERIT_STREAM;
                options->stdio[i].data.stream = stream;
            } else {
                Local<String> fd_key = env->fd_string();
                int fd = static_cast<int>(stdio->Get(fd_key)->IntegerValue());
                options->stdio[i].flags = UV_INHERIT_FD;
                options->stdio[i].data.fd = fd;
            }
        }
    }

    static void Spawn(const FunctionCallbackInfo<Value>& args)
    {
        Environment* env = Environment::GetCurrent(args);

        ProcessWrap* wrap;
        ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());

        Local<Object> js_options = args[0]->ToObject(env->isolate());

        uv_process_options_t options;
        memset(&options, 0, sizeof(uv_process_options_t));

        options.exit_cb = OnExit;

        // options.uid
        Local<Value> uid_v = js_options->Get(env->uid_string());
        if (uid_v->IsInt32()) {
            const int32_t uid = uid_v->Int32Value(env->context()).FromJust();
            options.flags |= UV_PROCESS_SETUID;
            options.uid = static_cast<uv_uid_t>(uid);
        } else if (!uid_v->IsUndefined() && !uid_v->IsNull()) {
            return env->ThrowTypeError("options.uid should be a number");
        }

        // options.gid
        Local<Value> gid_v = js_options->Get(env->gid_string());
        if (gid_v->IsInt32()) {
            const int32_t gid = gid_v->Int32Value(env->context()).FromJust();
            options.flags |= UV_PROCESS_SETGID;
            options.gid = static_cast<uv_gid_t>(gid);
        } else if (!gid_v->IsUndefined() && !gid_v->IsNull()) {
            return env->ThrowTypeError("options.gid should be a number");
        }

        // TODO(bnoordhuis) is this possible to do without mallocing ?

        // options.file
        Local<Value> file_v = js_options->Get(env->file_string());
        node::Utf8Value file(env->isolate(),
            file_v->IsString() ? file_v : Local<Value>());
        if (file.length() > 0) {
            options.file = *file;
        } else {
            return env->ThrowTypeError("Bad argument");
        }

        // options.args
        Local<Value> argv_v = js_options->Get(env->args_string());
        if (!argv_v.IsEmpty() && argv_v->IsArray()) {
            Local<Array> js_argv = Local<Array>::Cast(argv_v);
            int argc = js_argv->Length();
            // Heap allocate to detect errors. +1 is for nullptr.
            options.args = new char*[argc + 1];
            for (int i = 0; i < argc; i++) {
                node::Utf8Value arg(env->isolate(), js_argv->Get(i));
                options.args[i] = strdup(*arg);
                NODE_CHECK_NE(options.args[i], nullptr);
            }
            options.args[argc] = nullptr;
        }

        // options.cwd
        Local<Value> cwd_v = js_options->Get(env->cwd_string());
        node::Utf8Value cwd(env->isolate(),
            cwd_v->IsString() ? cwd_v : Local<Value>());
        if (cwd.length() > 0) {
            options.cwd = *cwd;
        }

        // options.env
        Local<Value> env_v = js_options->Get(env->env_pairs_string());
        if (!env_v.IsEmpty() && env_v->IsArray()) {
            Local<Array> env_opt = Local<Array>::Cast(env_v);
            int envc = env_opt->Length();
            options.env = new char*[envc + 1]; // Heap allocated to detect errors.
            for (int i = 0; i < envc; i++) {
                node::Utf8Value pair(env->isolate(), env_opt->Get(i));
                options.env[i] = strdup(*pair);
                NODE_CHECK_NE(options.env[i], nullptr);
            }
            options.env[envc] = nullptr;
        }

        // options.stdio
        ParseStdioOptions(env, js_options, &options);

        // options.windows_verbatim_arguments
        Local<String> windows_verbatim_arguments_key = env->windows_verbatim_arguments_string();
        if (js_options->Get(windows_verbatim_arguments_key)->IsTrue()) {
            options.flags |= UV_PROCESS_WINDOWS_VERBATIM_ARGUMENTS;
        }

        // options.detached
        Local<String> detached_key = env->detached_string();
        if (js_options->Get(detached_key)->IsTrue()) {
            options.flags |= UV_PROCESS_DETACHED;
        }

        int err = uv_spawn(env->event_loop(), &wrap->process_, &options);

        if (err == 0) {
            NODE_CHECK_EQ(wrap->process_.data, wrap);
            wrap->object()->Set(env->pid_string(),
                Integer::New(env->isolate(), wrap->process_.pid));
        }

        if (options.args) {
            for (int i = 0; options.args[i]; i++)
                free(options.args[i]);
            delete[] options.args;
        }

        if (options.env) {
            for (int i = 0; options.env[i]; i++)
                free(options.env[i]);
            delete[] options.env;
        }

        delete[] options.stdio;

        args.GetReturnValue().Set(err);
    }

    static void Kill(const FunctionCallbackInfo<Value>& args)
    {
        ProcessWrap* wrap;
        ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
        int signal = args[0]->Int32Value();
        int err = uv_process_kill(&wrap->process_, signal);
        args.GetReturnValue().Set(err);
    }

    static void OnExit(uv_process_t* handle,
        int64_t exit_status,
        int term_signal)
    {
        ProcessWrap* wrap = static_cast<ProcessWrap*>(handle->data);
        NODE_CHECK_NE(wrap, nullptr);
        NODE_CHECK_EQ(&wrap->process_, handle);

        Environment* env = wrap->env();
        HandleScope handle_scope(env->isolate());
        Context::Scope context_scope(env->context());

        Local<Value> argv[] = {
            Number::New(env->isolate(), static_cast<double>(exit_status)),
            OneByteString(env->isolate(), signo_string(term_signal))
        };

        wrap->MakeCallback(env->onexit_string(), arraysize(argv), argv);
    }

    uv_process_t process_;
};

} // namespace node

NODE_MODULE_CONTEXT_AWARE_BUILTIN(process_wrap, node::ProcessWrap::Initialize)
